Ibiquity Digital, Clear Channel, NAB and some lawmakers support the concept in filings describing possible conditions the FCC should place on Sirius and XM should the commission approve their proposed merger.

GM and Toyota said in a joint letter to the FCC this week that both companies offer satellite radio receivers as optional or standard features in addition to other entertainment features, like AM/FM analog radio. What the IBOC proponents are seeking, say the automakers, is “unprecedented” — a choice that would regulate the entertainment technologies in the car.

“HD is already penetrating the automotive sector without a mandate,” stated GM and Toyota. “Several manufacturers are either currently offering HD or have announced plans to make HD radio standard or optional in future models. Nothing in our companies’ respective agreements with XM inhibits our ability to offer HD radio.”

Calling IBOC “an evolving technology,” any mandate would reduce incentives to lower costs and further improve the HD-R product offering, according to the automakers.

In a recent filing to the FCC, Ibiquity estimated the cost of components to include HD Radio technology “in most satellite receivers” would be “no more than” $12–$15, as an IBOC baseband chip costs about $10, additional flash memory of $1 or $2 and a small cost for nonrecurring engineering. Ibiquity believes costs will decrease significantly once receiver manufacturers negotiate with suppliers for higher volume purchases.

Richard Lee, executive director of Satellite Radio Services for GM and David Danzer, group vice president, strategic & product planning for Toyota’s U.S. division, signed the letter.